The continuous process of breakdown and synthesis of biomolecules through chemical
reactions occurring in the living cells is called metabolism.
(i) Each of the metabolic reaction results in a transformation of biomolepules.
(ii) Most of these metabolic reactions do not occur in isolation but are always linked with some other reactions.
(iii) In these reactions, the metabolites are converted into another metabolite in a series of linked
reactions called metabolic pathways.
(iv) Each metabolite has a define rate and direction during the flow through a metabolic pathways called the dynamic state.
In living systems, metabolism involves two following types of pathways
(a) The anabolic pathway is called biosynthetic pathway. It leads to a more complex structure from a simpler structure, e.g., The pathway involving the conversion of acetic acid into cholesterol. These pathways consume energy.
(b) The catabolic pathways lead to simpler structure from a complex structure, e.g., The
pathway involving conversion of glucose into lactic acid in our skeletal muscles. This pathway lead to the release of energy, e.g., Energy is liberated when glucose is degrated to lactic in our skeletal muscles.